<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <script src="./js/test.js" async></script>
  <script src="./js/demo.js" async></script>
</head>
<body>

  <div id="app">app</div>
  <div id="title">title</div>
  <div id="nav">nav</div>
  <div id="product">product</div>

  <h1>哈哈哈哈啊</h1>
  <div class="box"></div>

</body>
</html>